package me.mingshan.leetcode;

import java.util.Arrays;

/**
 * https://leetcode.cn/problems/reverse-string
 *
 * 编写一个函数，其作用是将输入的字符串反转过来。输入字符串以字符数组 s 的形式给出。
 *
 * 不要给另外的数组分配额外的空间，你必须原地修改输入数组、使用 O(1) 的额外空间解决这一问题。
 *
 *
 *
 * 示例 1：
 *
 * 输入：s = ["h","e","l","l","o"]
 * 输出：["o","l","l","e","h"]
 * 示例 2：
 *
 * 输入：s = ["H","a","n","n","a","h"]
 * 输出：["h","a","n","n","a","H"]
 *
 *
 * @author hanjuntao
 * @date 2025/6/7 0007
 */
public class L_344_reverse_string {


    public static void main(String[] args) {
        char[] s = new char[]{'h', 'e', 'l', 'l', 'o'};
        reverseString(s);
        System.out.println(Arrays.toString(s));
    }

    public static void reverseString(char[] s) {
        // 首尾交换
        // 开始为i, 结束为 s.length - 1 - i
        for (int i = 0; i < s.length / 2; i++) {
            char temp = s[i];
            s[i] = s[s.length - 1 - i];
            s[s.length - 1 - i] = temp;
        }
    }

    public static void reverseString2(char[] s) {
        // 双指针
        int left = 0;
        int right = s.length - 1;
        while (left < right) {
            char temp = s[left];
            s[left] = s[right];
            s[right] = temp;
            left++;
            right--;
        }
    }
}
